Added icons, helperfunction and new fancy notice message

Added icons from webcrunch resp. heroicons
Added helperfunction to display inline svg with the plugin inline-svg
Implemented fancy notice message webcrunch. Realy nice but does only
work with javascript on.

app/assets/images/icons/outline/book-open.svg

@@ -0,0 +1,3 @@
+<svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke-width="1.5" stroke="currentColor" aria-hidden="true">
+  <path stroke-linecap="round" stroke-linejoin="round" d="M12 6.042A8.967 8.967 0 006 3.75c-1.052 0-2.062.18-3 .512v14.25A8.987 8.987 0 016 18c2.305 0 4.408.867 6 2.292m0-14.25a8.966 8.966 0 016-2.292c1.052 0 2.062.18 3 .512v14.25A8.987 8.987 0 0018 18a8.967 8.967 0 00-6 2.292m0-14.25v14.25"/>
+</svg>